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rocksdb/db/range_del_aggregator_v2.cc

196 lines
7.3 KiB

// Copyright (c) 2018-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "db/range_del_aggregator_v2.h"
#include "db/compaction_iteration_stats.h"
#include "db/dbformat.h"
#include "db/pinned_iterators_manager.h"
#include "db/range_del_aggregator.h"
#include "db/range_tombstone_fragmenter.h"
#include "db/version_edit.h"
#include "include/rocksdb/comparator.h"
#include "include/rocksdb/types.h"
#include "table/internal_iterator.h"
#include "table/scoped_arena_iterator.h"
#include "table/table_builder.h"
#include "util/heap.h"
#include "util/kv_map.h"
#include "util/vector_iterator.h"
namespace rocksdb {
TruncatedRangeDelIterator::TruncatedRangeDelIterator(
std::unique_ptr<FragmentedRangeTombstoneIterator> iter,
const InternalKeyComparator* icmp, const InternalKey* smallest,
const InternalKey* largest)
: iter_(std::move(iter)), icmp_(icmp) {
if (smallest != nullptr) {
pinned_bounds_.emplace_back();
auto& parsed_smallest = pinned_bounds_.back();
if (!ParseInternalKey(smallest->Encode(), &parsed_smallest)) {
assert(false);
}
smallest_ = &parsed_smallest;
}
if (largest != nullptr) {
pinned_bounds_.emplace_back();
auto& parsed_largest = pinned_bounds_.back();
if (!ParseInternalKey(largest->Encode(), &parsed_largest)) {
assert(false);
}
if (parsed_largest.type == kTypeRangeDeletion &&
parsed_largest.sequence == kMaxSequenceNumber) {
// The file boundary has been artificially extended by a range tombstone.
// We do not need to adjust largest to properly truncate range
// tombstones that extend past the boundary.
} else if (parsed_largest.sequence == 0) {
// The largest key in the sstable has a sequence number of 0. Since we
// guarantee that no internal keys with the same user key and sequence
// number can exist in a DB, we know that the largest key in this sstable
// cannot exist as the smallest key in the next sstable. This further
// implies that no range tombstone in this sstable covers largest;
// otherwise, the file boundary would have been artificially extended.
//
// Therefore, we will never truncate a range tombstone at largest, so we
// can leave it unchanged.
} else {
// The same user key may straddle two sstable boundaries. To ensure that
// the truncated end key can cover the largest key in this sstable, reduce
// its sequence number by 1.
parsed_largest.sequence -= 1;
}
largest_ = &parsed_largest;
}
}
bool TruncatedRangeDelIterator::Valid() const {
return iter_->Valid() &&
(smallest_ == nullptr ||
icmp_->Compare(*smallest_, iter_->parsed_end_key()) < 0) &&
(largest_ == nullptr ||
icmp_->Compare(iter_->parsed_start_key(), *largest_) < 0);
}
void TruncatedRangeDelIterator::Next() { iter_->TopNext(); }
void TruncatedRangeDelIterator::Prev() { iter_->TopPrev(); }
// NOTE: target is a user key
void TruncatedRangeDelIterator::Seek(const Slice& target) {
if (largest_ != nullptr &&
icmp_->Compare(*largest_, ParsedInternalKey(target, kMaxSequenceNumber,
kTypeRangeDeletion)) <= 0) {
iter_->Invalidate();
return;
}
iter_->Seek(target);
}
// NOTE: target is a user key
void TruncatedRangeDelIterator::SeekForPrev(const Slice& target) {
if (smallest_ != nullptr &&
icmp_->Compare(ParsedInternalKey(target, 0, kTypeRangeDeletion),
*smallest_) < 0) {
iter_->Invalidate();
return;
}
iter_->SeekForPrev(target);
}
void TruncatedRangeDelIterator::SeekToFirst() { iter_->SeekToTopFirst(); }
void TruncatedRangeDelIterator::SeekToLast() { iter_->SeekToTopLast(); }
RangeDelAggregatorV2::RangeDelAggregatorV2(const InternalKeyComparator* icmp,
SequenceNumber upper_bound)
: icmp_(icmp), upper_bound_(upper_bound) {}
void RangeDelAggregatorV2::AddTombstones(
std::unique_ptr<FragmentedRangeTombstoneIterator> input_iter,
const InternalKey* smallest, const InternalKey* largest) {
if (input_iter == nullptr || input_iter->empty()) {
return;
}
if (wrapped_range_del_agg != nullptr) {
wrapped_range_del_agg->AddTombstones(std::move(input_iter), smallest,
largest);
// TODO: this eats the status of the wrapped call; may want to propagate it
return;
}
iters_.emplace_back(new TruncatedRangeDelIterator(std::move(input_iter),
icmp_, smallest, largest));
}
void RangeDelAggregatorV2::AddUnfragmentedTombstones(
std::unique_ptr<InternalIterator> input_iter) {
assert(wrapped_range_del_agg == nullptr);
if (input_iter == nullptr) {
return;
}
pinned_fragments_.emplace_back(new FragmentedRangeTombstoneList(
std::move(input_iter), *icmp_, false /* one_time_use */));
auto fragmented_iter = new FragmentedRangeTombstoneIterator(
pinned_fragments_.back().get(), upper_bound_, *icmp_);
AddTombstones(
std::unique_ptr<FragmentedRangeTombstoneIterator>(fragmented_iter));
}
bool RangeDelAggregatorV2::ShouldDelete(const ParsedInternalKey& parsed,
RangeDelPositioningMode mode) {
if (wrapped_range_del_agg != nullptr) {
return wrapped_range_del_agg->ShouldDelete(parsed, mode);
}
// TODO: avoid re-seeking every call
for (auto& iter : iters_) {
iter->Seek(parsed.user_key);
if (iter->Valid() && icmp_->Compare(iter->start_key(), parsed) <= 0 &&
iter->seq() > parsed.sequence) {
return true;
}
}
return false;
}
bool RangeDelAggregatorV2::IsRangeOverlapped(const Slice& start,
const Slice& end) {
assert(wrapped_range_del_agg == nullptr);
// Set the internal start/end keys so that:
// - if start_ikey has the same user key and sequence number as the current
// end key, start_ikey will be considered greater; and
// - if end_ikey has the same user key and sequence number as the current
// start key, end_ikey will be considered greater.
ParsedInternalKey start_ikey(start, kMaxSequenceNumber,
static_cast<ValueType>(0));
ParsedInternalKey end_ikey(end, 0, static_cast<ValueType>(0));
for (auto& iter : iters_) {
bool checked_candidate_tombstones = false;
for (iter->SeekForPrev(start);
iter->Valid() && icmp_->Compare(iter->start_key(), end_ikey) <= 0;
iter->Next()) {
checked_candidate_tombstones = true;
if (icmp_->Compare(start_ikey, iter->end_key()) < 0 &&
icmp_->Compare(iter->start_key(), end_ikey) <= 0) {
return true;
}
}
if (!checked_candidate_tombstones) {
// Do an additional check for when the end of the range is the begin key
// of a tombstone, which we missed earlier since SeekForPrev'ing to the
// start was invalid.
iter->SeekForPrev(end);
if (iter->Valid() && icmp_->Compare(start_ikey, iter->end_key()) < 0 &&
icmp_->Compare(iter->start_key(), end_ikey) <= 0) {
return true;
}
}
}
return false;
}
} // namespace rocksdb